344 CALLITRINEAE [CH. 







be in favour of including this Lower Cretaceous genus among the 

 Coniferales and regarding it as probably allied to the Callitrineae. 

 But the data are insufficient to form the basis of any definite state- 

 ment as to the position of the genus. 



I Frenelopsis Hoheneggeri (Ettingshausen). 

 I Frenelopsis occidentalis Heer 1 . 



Though the specimens referred to these two species may be 

 correctly separated their close agreement in habit points to a 

 single type so far at least as concerns the characters as a whole. 

 The specimen represented in fig. 763, A, B, originally described by 

 Zeiller from the province of Gard, illustrates the method of branch- 

 ing and the form of the leaves borne in whorls of four. Schenk, in 

 his account of Lower Cretaceous material of F. Hoheneggeri from 

 Wernsdorf in the Carpathians, states that the leaves are in decussate 

 pairs or sometimes in verticils of four. The epidermal cells have 

 straight walls and a thick cuticle; the stomata form longitudinal 

 rows on the internodes and are characterised by the presence of 

 4 5 accessory cells overarching the stomatal depression 2 . 



Specimens described from Bohemia by Velenovsky 3 as F. 

 bohemica resemble F. Hoheneggeri both in habit and in the structure 

 of the stomata. 



Frenelopsis ramosissima Fontaine. 



This species is represented by numerous well preserved speci- 

 mens in the Potomac formation 4 : some of the stems have a diameter 

 of 5 cm. and lateral branches are given off in whorls of 3 5 ; there 

 are three leaves at each node with broadly triangular apices and 

 concrescent decurrent bases as in F. Hoheneggeri (fig. 763, C). The 

 stomata are arranged in longitudinal rows and- agree in the posses- 

 sion of a rosette of accessory cells (fig. 763, D) with F. Hoheneggeri: 

 several of the epidermal cells are provided with short spinous pro- 

 cesses 5 . This species is represented by specimens showing clearly 

 the cupressoid habit of the smaller foliage- shoots (fig. 763, C). 



1 Heer (81) p. 21, PL xn. figs. 37; Saporta (94) B. pp. 139, 199, 214; Pis. 



XXXVI., XXXVIII. 



2 Thompson (12 3 ). 3 Velenovsky (88) figs. 13, 10. 



4 Fontaine (89) B. p. 215, Pis. 95101; Berry (11) p. 422, Pis. LXXI., LXXII. 



5 Berry (10 2 ). 



I 



